Spring suspension for vehicles



Febe 23 1926.

F. l.. o. wADsw'oRTH SPRING sUsPENsIoN FOR VEHICLES l 4 Sheets-Shee't 1 Fil'ed Feb. 2l. 1921 llmnum mullul `Feb. 23,1926. I 1,574,139 `r'.| o. wADswoRTH f n SPRING SUSPENSION FOR .VEHICLES l l Filed Feb@ 21, 1921 4 sheets-sheet 2 Feb. 23 1926.

. 1,574,139 F. L. O. WADSWQRTH SPRING SUSPENSION FOR VEHICLES Filed Feb. 21. 1921 I// l/E 41;

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SION FOR VEHICLES SPRING SUSPEN Filed Feb. 21 1921 4 sheets-sheet 4 raar@ FRANK L. r WADSWORTELOF ITISBURGI-, PENNSYLVA'NA.

i srniiie sUsrniiisroiv' non vniiiciins.

Application lled liebri'iaiy 2 l'e it linoivn that l,- Fniivi; L.. O; Vilainsivfiii'rir, a citizen of the-United States,fre siding at Pittsburgh, in the county of filleglieiiy and State oi Pennsylvania, have "invented cert-ain new Aand. usel'iil iiiprove ments iirSpring Suspensions iorVehicles, of which the 'tolloivingis a'"speciicffition lily inventionrelates to improvements in slioclr absorbing devi-ces which'v arevpalrticu-l .hii'ly designed ,tosupplement the actionof the iisiial terms or spring siispensionjsytenis Jor the bodies or automobiles,orotlier Wheeled vehicles. iYOrganiZationsfo-f this character may bc dividedinto tivo'geiieral groups; one group comprisingthose types and -forms lott apparatiis infivli'ich the suppleinental'elements ofthe system "act 111 parallel with theinain spring` membersy and serve only to reinforce and stiffen the' action ol the latter in resisting either conipi'essive shocksci rebound stresses and another group or' devices inf ivliicli the supplemental, or secondary, springs--or other equivalent cushioning 'elements-are 1nsorted between some portion, or portions, of the primary suspensionA #springs and kthe part or nii'ts, of the vehicle A traine :o r chas. toivliich said members are ordi* iiarily attachedVv directly; "and iii 1 which, therefore, the supplemental andthe main suspension menuisiers act in series ivitli .one another. rlhis second group of `organizatifiins-vliicli are generally designated as .supplemental suspension `systenis-present certain advantages over the iirst mentioned organizations, ivliicli are usually referred to Vas suiipleiiiental-reintorceinent systems; the inostmportant of these advantages being the capacity vot thesupplemental-suspension elements to resist and ciisliion'the elccts et the iiiinoi shocksand jars that :aiinot be taken up,and'absorbedhy,the stilici .main spring and to tliiisgreatly increase' the sensitiveness and easy riding7 qualities oit the suspension Vorganization as l a whole. But these advantages are attained at the seci'iiice of tliatcharaeteristicwhich iiialres the supplemental-reiiiforceiiient`fsys tenis particularly iiscicuhviz," the capacity ot the added secondary elements to increase the load carrying capacity of the vmainl spi-ing members and to also `resist or damp or otheriviS-e restrain the `normally tree elastic oscillations ofthosepriniary niembers,

1,119.21. `serial ivo; 44eme.'

@ne of the generic' purposes. of my pres ent invention is to provide a new type of coiiiplemental, or of supplemental-compleinentah 4saspensionsystem, which presents the more desirable and advantageous'cliaracteristics of both the reinforcement and the suppleinentail-suspension types or yorganization; i. e., to provide acoinbina'tion otinain spring and secondary spring elements which ai'econnected at tinies in'series and .atlother times inl parallel; fand which therefore cooperate effectively iii',both cushioning and absorbing the` vell'ect of minor `shocksand jars, and :in also resisting VV'and restraining the excessive iieiiures andv oscillations' that I`tend to occiir when thesystein is subjected to unusual loads or abnormal stresses. v

"if'iother important` object oftliisjinvention 11s tlieprovision. 'of a type ofconiple- `niciital suspension organization, of the chaiacteijustindicated, which' iscapable, not only oic efficiently resisting and cushioning both the minor and the maior shocks of *conipressioin but of* also quickly and effec- V1body pai-.ts When the vehicle is beingldriven over rough paven'ients.

A' i rt-her'fspecilic obiect of my present improvements is 'to provide `the complementat suspension. organizations lierei'nbefoie generally described ivitli means orpreventing anysubstantiallateral displacement or 7the vertically oscillating body and running gear parts; `and thereby preventing both side sway o1' rolling'aiid end rocking or pitching of the tonneau on its axle mountings. rlhe preventatio-n of side sivayor cross rolling, ot" tlie vehicle *bodyh is of great iiiipoitance in the icas-e of heavy liighspeed cars becaiiseaiiy such movement-sparticu-V larly i'vlien it is accompanied by a rebound or excessive upthi'oiv koit vthe `suspended body-fis highly)unpleasant, andinay be 4danger'ous 'when' the vehicle ris being' driven around' corners atfa l'1igli"`speed ,'oi over a I`lateially tilted'- oi" slopiiig'road surface.

Other characteristic" features and objects of particular einbcdiiiients of n lgeneric in-` 4veiition will' be inade apparentrtotlio'se skilled in 'this' artlby the* exlaniinati'oiifjo'f the 'various V illustrative examples et' p' my :fim-

proved type of organization which are depicted in the accompanying drawings and hereinafter more fully described. All of these features may be either conjointly util-- ized in a single eXemplificat-ion of my invention, or may be used separately, or to such extent as desired, in different embodiments thereof; and it will therefore be understood that the various forms of construction herein disclosed are to be considered only as typical forms of my improved coinplementary suspension system, and are not to be regarded as limiting the mechanical scope of that system.

1nk the drawings, which constitute an essential part of the present specification, Figs. 1 to a inclusiv'e show one form of my invention as it may be used in conjunction with an ordinary side leaf spring support for arear axle. Fig. 1 is a longitudinal vertical section on the central piane of the system e. g., the planes 1 1 of Figs. 3 and 4 Fig. 2 is a side elevation of the saine system showing the parts in the position which they assume on a rebound or upthrow of the elastic members above the normal or static vload position of Fig. 1; Fig. 3 is an end view of the parts just to the left of the plane 3 3 of Fig. 1; and Fig. 4 is a partial cross-section on the plane 4 4: of the tirst figure.

Fig. 5 is a vertical sectional View, similar to Fig. 1, showing a second embodiment of my invention the normal load position of the main and supplemental spring elements being depicted` in full lines, and the compressed and expanded (or rebound) portions of those members being indicated in part in dotted lines-and Fig. 6 is a partial sectional view of certain parts of this construction when subjected to maximum load stress.

Figs. 7, 8 and 9 illustratea thirdapplication of my invention to the side leaf spring support of a front axle of an automobile or similar vehicle. In these illustrations, Fig. 7 is a side elevation of the `organization as it appears when subjected to normal load stresses; Fig. 8 is a cross section on the plane 8 8 of Fig. 7; and Fig. 9 is a. similar section on the pla-ne 9 9 thereof.

Fig. 10 is a vertical sectional view on the central plane 10 1O of Fig. 13 of anlother exemplication of my improved complemental suspension system with the parts in the normal load position of static equilibrium; Fig. 11 is a partial side elevation of this same construction with the primary and secondary suspension members in the position of extreme rebound; Fig. 12 is a detail cross section on the horizontal plane 12 N G of Fig. 10; and Fig. 13 is another cross-section on the plane 13 13 of Fig. 10.

Fig. 14 is a vertical'sectional view s'imilar to that of Fig. -10 showing a further rrltgll 0f my .improvements 'to a iront side leaf spring member of a vehicle chassis; the static load posit-ion of the parts being indicated in full lines and the extreme compression and eXtreme rebound positions of the spring members being indicated, in part, by dotted lines. Fig. 15 is a detail crosssection on the plane 15 15 of Fig. 14.

Figs. 16, 17 and 18 depict still another embodiment of my invention. The first of these figures is a sectional elevation through the central longitudinal plane of the main spring member (el g., the plane 16.-16 of Fig. 18); the second figure is a side elevation of a portion of this construction, and shows the parts thereof displaced from the normal load position shown in Fig. 1G, to a position of abnormal rebound or recoil; and the third figure is a detail cross-section on the plane 18 18 of Fig. 1T.

Figs. 19 to 22 inclusive illustrate a seventh typical exemplitication of my prese-nt iinprovements. In this illustration Fig. 19 is another sectional elevation on the central plane of the main side leaf spring element y(e. g., on the plane 19-19 of Fig. 22) g Fig. f 2O is a side elevation, showing the parts displaced from the position of static equilib- V iuin (Fig. 19) to the position of extreme recoil' or expansion; Fig. 21 is a horizontal section on the plane 21-21 of Fig. 20; and Fig. 22 is a partial vertical section on the plane 22-22 of Fig. 19.

Fig. 23 is a composite illustration of another embodiment of the present invention. The full lines of this ligure show the parts in the position of static equilibrium (i. e.,

of normal load) and the two sets of dotted lines show the primary and secondary spring members both in the position of extreme compression and in the reverse position of abnormal rebound.

Fig. 2li is a central sectional view similar to the corresponding views of Figs. 1, 5, 10, 1li, 16, 19 and 23 of still another form of my improved complemental suspension organization; and it shows in full lines the position of the parts under normal load and.

in dottedl lines the corresponding position .und-er an increased kinetic load or compressive slioclr. Fig. 25' is a detail cross sectional viewfon the plane 25 25 of Fig. 24..

Figs. 2,6 to 29 inclusive', depict stillranother application of my improved complemental suspension combination to the rear axle support of a truck or other heavy veliicle. In these illustrations Fig. 25 is a side elevation of the construction and shows thc parts in normal load position; Fig. f2.7 is a central sectional elevation showing the spring `suspension elements in the position which they assume under a severe compressive shocl; Fig. .28 is an enlarged section on the plane '12S- 2S of Fig. 26; and Fig. 29 is a vertical section on the plane '25? 29 of Fie 127i lbd sion, and `3rd,- adetail section-on then-plane qll ,- ln the@ following `detail description, ythe 1sa1ne,-or similar, reference characters are alyWays used, as iai' as practicable, .to designate .analogousorcorresponding parts ol Ithe diltere'nt exemplary embodimentsogtnmy' ini- -pioveinents.

Considering-inst -tlie'-construction illustrated iii-Figs.` l td l inclusive: 2 indicates a finiinyside; leaf spring Wliieh is `pivotally attachedw-atits-inner end (not-shown)- Yto ythe -vehiele body, Yi111` thenisuali manner,- aiid Ais -bolted' at; its :Centerr to' the main aigle -block rlGlie outer end of this springisordinarin ly coupled to the body member 6 by n'ieans of longitudinally rigid or solid shackle links that are pivote'd, at one end, to vthe soiled eye of the main spring 2,'and at the lotherendto-ithe saidwmember 6; butin the :application of my invention-fand vas a part thereot'wtliese `rigid links are replaced by ay vertically flexible-connection, which permits "this part of Ithe mainfspring' toinove bodily up l andy down, 'through acertain distance,

with `respectfto the body, butwliich issoconthis `l1vertically ifiexible'biitf laterallyrigidY -stiiicted as to prevent any relative sidewise play or displacement of the tWo-coniiecterfl parts. ffln-the'forin shoWnin liggs. l' and coupling-coingrises a broad l"lshap,ed`l traine P(,Ethat is pivoted atl its upper end Aon the -body shackle bolt 11,1and a rigid U-sliaped linkj let, 'that ispivoted its lower forked 4end on -Lthe main 'sp-ring' eye bolt 1?,-and a longepintle lor. hinge pin boltO that Iconiieets-tlie adjacent extremities of the said 'fr-aine land link. i A Icertain ranlgeot' -ielatively :free movement, of the enter-end ot tlieiinaiii ,spring and the body, ispermitied :byftlie hinge action ofthe two pi-votally connected members 'TQ-lli; but this range is -Yrestricte'd iii 'one 1r direction i by the Contact engagement of the-link, il, withy the lon/'ei' side oli the Atriniigular cross bar 'oit tlieeupper frame 'i' (see di'itted'lvliiie vposition C ot "Figg l) and, in -theotlier direction., by the reciprocal .engagenieiitfo the link -baiex-` tensioni oivstop Qwith the opposite .side-'ofvr Jtliisvsame crossbarwGsee-dotted lineposirtioiiltof Fir):l l, for-full liiiefposition-oii Figi' 'ran'ie or tonneau. "also Connected, at"an,intermediate parainits ,lengthf the )airJtLlinks13G-436 and "the piiitle end oi tlieinain spring 2. fissubjected. to an z-ii'ici" 2). #-Diiringgtliis 'treeyeiticalincitementor` the connected main spring and body ineinbers' the outeijipart of they 'primary'suspension element is not 'subjected toy any flexural strain., aiidftliei`"efoie'assumes its initial or iiiistiessed forni ,"JbutA as soon asftliereis a 'Contact 'engagement between the 'connector elements? vand lfhtlie latter :are locked against u'i'th'erliinge inoyei' ent inthe-f une direction and :the locked 1 i'ts then act as a solider vertically rigidfshaekle link, and communicate `the: b'ody load tothe 'free 'of the inain spring,` 2.' "lllie letter' nien bei.' 'thusV brought into 'play 'tof'elastically resist furthermovement olfthe shaekled parts either 'toward or away from each other.

The other part or vportion VVof my invention-#Which cooperates with ,the 'coupling e'i'ii'ineeti'on, l'hl-QOWQB," in controlling,`

lSe

and complenientii'igthe4 actionofftlie inain 'si'oring Q--coinprises a." secondary spi-ingun'it inter osed1 between the `vehicle"liiod7` and 'the relativelystiii centralv portionllot' ,iles-and then in parallell therewith, -to` successively' cushionlaiid' absorb notion-ly the fminor oscillations. and vibrations, but also 'the'abnorn'ial' and excessive kinetic stresses 'andfsliocks'foi rough road: traif'el.A ln this iirstldescribed' exeinpliiication the secondary or auxiliary unit comprises a volute oi" iiis- 4to-, `z`onical coil' spring :'24, which is supported 'on a'inain 'spriiigseat"2$, 'and is ei'ilig'agged, 'atx its upper-end, by the head QZfthat is piy'otally ,nioi'iiited between' thef'orked ends of a'lever"ineniberQ. 'This-lever iiiei'nliei f is, intui'n, piyotally connected, at its voppositej'extremity` 31,to a 'second lever 32, vwhichisfi'otatalgily mounted, at 323, in the lslott'e'd bloick that is bolted to tliob'ody 'ihetirst lever `eier-.rent is Vith "the aille bracket 5, bjyfineans of .block 37; andthe second lever '32 is 'provided .with an'ent'ei'ision ai'nilltliat is adapted to engage-4v-in`'the normal.4 loadand rebound (position ofthe parts-With Athe lon'eriace o-tlieblock (seeliiillline positions lilies.

1 and 2).

.The essential' features oit opei'ai'ioiioig the ,mechanismv above described,` arev as ollows:

,In-thevi'iornial load Vposition of the parts the .adj acentffaces I oiiftlie itivo levers 30 and 32 .afreyin .Contact engagement at median poi'- tions of their lengl'th, and the outer; forked ends ,of theiirst ,lever are also' ei'igaged by Vthe body sill, 'thereby preventing any fui'- tweeiithe heads 2G and 2T 1 trt 'olif the' loa-d ed'. to' 'the outer lli'heii the! lSyste'in .thatl is ordinai'il 1' tiansiiL.

5S, 0;.- -rrcoinpree'siye s'l'io l exi@ parte move toward' @zich ether;

he,v body,- andw andthe lili) iio Vthe movement thrust of the link connections 36, rocks the two engaged levers and 32, as a unit, on the cross bolt 33; thereby compressing the supplemental spring 9A between the oppo- .sitely moving heads 26 and 27, and interposing a continually increasing secondary spring resistance to the approach of the said parts. ment the outer end of the main spring 2 may move freely toward the body bracket 6 without any elastic flexure of this part of the primary suspension member; and the minor kinetic stresses and shocks are therefore taken up entirely by the highly sensitive and elastic coil spring 24: which acts as a supplemental series suspension for the free end of the main spring. But as soon as the `movement has carried the outer eye of the primary spring to the position, C', the link coupling elements 7-ll are locked on each other; and any further approach of the body and axle parts is now resisted not only by the continued lever-flexure of the auxiliary coil spring 2d, but also by the progressively augmented bending of the outer partof the main spring 2. During this later portion of the primary and secondary suspension members therefore act in parallel, to reinforce and complement each other,

Y in quickly restraining and absorbing the effects of excessive load stresses and abnormal or unusual shocks of road travel. llVhen the closing movement has proceeded to such a point that the lever system, 30-31-32, has

' been rocked through the extreme angle n-c (see Fig. 1) the further iexure of the spring supports is arrested by the engagement of the connected ends of the levers with the body sill of the tonneau, (see dotted lines at left of Fig. l), thereby preventing rupture, or injury, of the coil Qd by undue compression. As the members return to the first position of static equilibrium (N) the part of the load stress carried, in parallel, by the outer end of the primary suspension member Q, is gradually transferred to the secondary suspension coil 211i, thereby permitting that part of the main spring to again assume its initial untiexed form. lVhen a rebound or expansion movement occurs, the body and axle parts separate from one another without, atvfrst, imposing any reverse bending on the main spring; but the link connections $56 now act as tension members and roc-k the lever 30 downwardly on. the pivot bolt 3l- (the lever 32 being prevented from moving downwardly by the contact engagement `between the parts and 38)-thereby again compressing the secondary suspension spring 24 against its main spring seat 2G. rl`he relative position of the pivot bolts 3l and 38, with respect to the link connections 36, is such that the ratio between the bodily movement of separation of the suspended parts and the angular movementof the spring- During the first part of this move-Y compressing lever 30 is much greater than in the reverse closing movement of the system;

and the restraining effectv of the secondary cient to arrest the expansion of the system before the free outer end of the main spring has reached the rebound position, R, in which it has been again actively coupled to the body bracket by the locking of the linkage, 7-14-20, into a vertically rigid shackle. But the link parts, 7 and 23,-may be so proportioned, as to arrest the vertically free movement of the eye `17, at any stage of compression of the supplemental spring 2e; and when this arrest takes place the further opening or expansion of the elastically coupled members is resisted jointly by the continued positive flexure of the secondary spring and the concurrent negative or reverse bending of the primary spring. The rebound action of the combination therefore involves the same sequence of series and parallel cooperations of the supplemental and main spring members, as is characteristic ofthe compression action of the system.

rl`lie various elements of structure already described may be used by themselves, in the manner above explained; but I sometimes prefer to provide means for damping or braking the recoil of the flexed springs from their positions of compression or expansion g., C or R) to their position of static equilibrium (N). ln the construction depicted in the iirst four figures of the drawings, these means comprise a wedge shaped block 39 which is slidably mounted in the slotted base of the block 85, and is pressed against the curved upper edge of a central tongue on the lever extension 8S, bya spring all). ld/Tlien the lever system 3-3132 is rocked downward as a unit (on compressive movements) the block 39 is pushed backward into the widened opening between the base 35 and the tongue on the lever extension 38; and the recoil or return action of the compressed parts is damped or slowed down by the combined frictiona and spring resistance of the elements 39 and 4t() to the pward and forward thrustof the lever eK- tension 3S. The damping control means for the restraint of recoil movements from rebound position comprises a hardened steel block or ioll Lil, that is mounted in the slotted end of the upper lever 82. and is pressed into the wedge shaped opening between this lever and the adjacent portion of the lever 30 by the concealed spring TWhen the two levers are separatedby the expansion of the system--as shown in Fig. Z-the roller Lll is pushed to the left by the spring 42; and when the compressed spring 24 tends to recoil, the return movement of the lever-'spring elements 24.-30 to normal position is restrained and decelerated by the spring; pressed fricti-onal. engagement of the lelements #l0-42 with the mutually inclined lcompressed condition; and..V may therefore n add to the efficiency of the combination in quickly overcoming` the effects. ot excessive andl A'frequently repeated. shocks. Brit, as already indicated, myfimproved supplemen talecomplementil-spring suspension system maybe used either with orwvithout the auxiliaryv friction control. restraints, which have just been considered. Y y

The tornil of construction shown in Figs. 5. and 6 designed oimnse in conjunction with a three-quarten-elliptic main spring, which consists of the. semifelliptic side vleaf spring 2, bolted at its. center. to 'the axle block` 5, and thes'croll springt?, bolted at its base Vto the body. bracket 6. In the ordinary use ot this form on. suspension the adjacent eye ends of these t ao. elastic elements are joined by aA longitudinally rigid radius linl:` or shackle, that maintains 'the conjoined extremities at a tired andy invariable distance from each other; but in this second; example of n-,y impr red organization the rip-id shackle connection is replaced by a. vertically flexible frame, which com-prises; lthe. solid link lthat is pivotall'y supported at l1 on thebocy braclietb; the cross links. let-ll that er. piroted, to the eye bolt "g the let shaped. radius link, 43,. that is likewise pivoted, at lle, to the eye ofthe scroll spring2j-15 and the pintl'e bolt 2Ou that flexibly con: joins the inner. ends oit. the three link mem.- bers Tf1-le, and` e3. .lt Will be .apparent that this linkage will permit the outerend ol the main springh to more `freely in vertical plana ont imposingany substantial .dorure on either` ot `iheelastic,elements 2:01* rmtilV the upper fdo et the semi-elliptic element eo sin contact Withthelowerend o' link 7 dotted line posi- GQ 5 or nntiljthe eye ot this rient engages with the head ot the i 1: e3 (see dotted line position, Rv, ed); andv that after such contact; engage'- nients occur both oit4 the primary suspension membersY will be subjected toa portionoion,

the displacement stresses imposed on the bod-y and;` anleputs, and will, be concurrent ly .nd proportionally flexed thereby, as the 1; @vement continnes. But it will also be apparent tha-tthe linka-ge frame will prevent any lateral or sidewise Y movement of the cross connected ends of the main spring elements 2-2a with respect to the body frame; andv will thereby check any tendency to` side sjwliy or crossrolling;l` ot the vehicle tonneau on its running gear supports.

The snpplen'lental-comfplementall sprung unit which cooperates with the interconnected. main spring' elementsv 2--2ZL comprises; a highly elastic multiple leal' spring 221@ that s-.engag'ed at its outer eye-end with :rossslot inthe hanger, 7, and is rigidly securedy at its base to, ay lever ele-ment 30?,

.Whichis, in turn, rotatably supported, by

the cross. bolt SLL, sint-he end ot' a second lever 32e. The la ter member is pivotally fronneeted, at its` oppostel extremity, to the slottedv block 35, which isI bolted` to the'body frame of the vehicle, and which is; provided Withl side` lugs, 45, that engage ivi-th the lower edgesof the lever and prevent it from movin-,q` downward-ly on its pivot connection 33t The inner end of the first leverv 30a isalsoconnected,A bythe ljinlcs 36u-36, with the: axle bracket 5*; and; this lever isgnormally held; in non-rotatable 'relation to' its sister mem-ber 32% by a pressure Contact engagement betweenr ythe adjacent edge por-` tions; of,` the two, levers. The upper lever 32a is preferably recessed on its lower side to` receive4 two `Wedge shaped blocks. 39?: and lila, that arepresscd apart by'a springlO?, and a-retghnsrespectively held ini tnictonal engagement with the central connecting rib o'l'- thelugs 425,' and; the. upper',A curved edge oig the-lever arm 30?.' Thebasefportion of the supplementalspring, 2l?, is also pret'- erably connected;l to a pail-fot auxiliarycoil springs, 46+el`afivhiehf are mounted on opposite sides of; the mainleaf. spring, 2, and are flexibly secu-red theretoby means of the clip, 4.7,

rEhe functional ac-t'on o'lzrthis organization rollo l:V ln the position of static equilibrium, N, (sliown in 'full linesin Fig.

tithe secondary springs Maffeiare' under is miicient. y mit 4 tensonto carry all` that p reoithe loadgthat is ordinarily supported by thepconjoined ends, of; the springs` 2 and 2% llheirthe sysnn, issubjected to van d. ,l ietic stress,A or( compressive shed, the thrnsl` of the link. connections, 365%3595 lifts; the interengaged lever *sys*` tem, as-a unit, and imposes a progressively increased flexing strain Vonthe secondary .spring elements 24%46. As this action con tinnesf thflee endg of; the main spring, 2, cemesyinto engagement with the rigid linlr bar, .7 ,1, and4 receives `there'from aicontinually increasing,proportion the loadf or compression stress, which is then carried in' parallelrby both the primary and secondary suspension elements. The yclosing movement may continue until the lever .system has been rocked through Vthe angle, ngc, and the spr.:ng-lever-elements 2-Jea--3Oa-"2a Ahave thus been brought into engagement with the under side of the tonneau or body frame (as shown by the dotted lines c-c-c of Fig. 5). ln this phase ofthe action the lever 32a moves away from the lug members iti-45; and the block 39 is thrust into the widened opening thus formed by the spring 40 (as shown in the detail view of Fig. 6). lVhen the kinetic compression stress is relieved the flexed springs, 2 2, 24t"-1l6, tend to recoil to their original static load position; and the violence or rapidity of this recoil movement is restrained and diminished by the frictional engagement of the spring pressed block 3Q with the surfaces on which it must slide outward as the lever system moves downward.V ,y L

l/Vheii the suspension system is subjected to a rebound or opening stress, that causes it to expand beyond l.the normal load position of the parts, the links 36u act as tension elements and rotate the lever 30 in a counter-clockwise direction on the pintle pin 31a; the second lever 3- being held against reverse rotation by the stop lugs 45. The resultant upward movement of the leverspring element 24a imposes a rapidlyincreased flexure onv both the secondary leaf .spring and the auxiliary coil springs 46; the tension on the latter being augmented by the relative downward movement of the lower .support 47. During this initial phase of this supplemental-spring suspension alction the outer end of the main spring, 2,Y l1s free to move away from the body support without imposing any appreciable bending stress on its associate member 2a; but when the eye of this primary suspension member comes into engagement vwith the base of the U-shaped link 43 (position R), both of the man leaf spring elements 2--2LL are subjected to reversebending strains'that cooperate in parallelwith the positive tensions of the secondary springs to quickly checkV any undue or abnormal `separation of the spring Vconnected parts. V/Then the Vlever 3()a has been moved through the angle, 'M -7, (Fig. f5) the intermediate portion of the supplemental leaf spring 24a is brought into engagement with the rlower side of the `body frame, and the stiffness, and load carr Ying yca1 acit of that element is thereby greatly increased; so that any` excessive Gil rebound (beyond the postion R-r, etc.) is thus effectively prevented, without imposing any dangerous strain on the elastic suspension members. Y The .rapid recoil of the flexed springs-after the rebound` movement is arrested-is damped and retarded lthe secondary spring caps 27", and w by the` frfctional control action of the spring actuated block el, which is pressed outwardly into the wedge vshaped opening between the .stationary lever 32a and the moving lever 30a.

rlhe recoil check elements 39-l()a/ll (like the corresponding parts of the -iirst described construction) are not essential to the proper functional performance of my 'supplemental complementalspring combination; and. may be omitted when it is desirable to obtain a very free undamped action of the suspension syst-em. fnd if any of tl ese parts-when used-should be accidentally lost, or if, through injury or wear, they should cease to perform their intended il'unctions, the action of the other Y elements of rthe coi'iibination will not. be injuriou'sly affected, nor will the operation of theorganization, as a whole, be interrupted or sensibly disturbed.

Figs. 7 ,18 and 9 depict a form of supplemental-snepension-reinforcement mechanism which may be advantageously applied to a lside leaf spring support for the front axle of an automobile or similar vehicle. These front axle 'springs are pivoted, at their outer ends, on riaid hanger arms that project forward from the tonneau frame; and are ordinarily connected, at their inner ends, to i the. body sills by means of swinging shackles. lnthe use' of my invention these `shacl'- les are replaced by a vertically flexible, but laterally rigid, linkage, which is similar to the `one 'shown more in detail in lFigs. l and. and which comprises the H-shaped frame. "i", the forked end bar lill, the stop extension 23"k thereon, and the pintle bolt connection 201.y Thislinkage, which is pivotally connected at its extreniiities with the body sill block, 48, and the adjacent eye of the main spring 2, respectively, permits of a certain range of free vertical movement between the connected parts; but it becomes longitudinally rigid, or vertically inflexible, when the link bar lab-23b assumes either of the dotted line positions C or l" and it then acts, as a solid shackle connection, to transmit a certain proportion of the load or rebound stress tothe inner end of the primary suspension member.

The supplementalsuspension reinforcement unit, which is interposed between the centralor intermediate part of the main spring and the vehicle body, comprises, in this case, a pair of volute coil springs, 2l"- 21lb, arranged one on each side of the member 2, and supported thereon by the saddle frame 26h; and a single twin-arm lever 30b-30b, which carries at its inner end hich is linked', at an yintermediate point of its length, to the axle block, 5, by means of the bar 36h and the clip block 37. This loo` lever is also provided with two" cross-bolt is used in the transmission and differentialY geur chambers ot an automobile. y

The operation ot' this third illustrative embodiment of my invention is essentially the saine, in principle, as that which characterizes the tufo previously Vdescribed constructions. ln they normal load position ot the parts, the inner'ends of the lever arms 30h, and `the spring caps :27h carried thereby,

are in engagement with the body frame 6;VK

and the su'iplenientalsprings are under suiiicient initial tension to balance all that portion ot the load that is ordinarily supported on the inner eye end of theinain leaf spring` 2. This normal load` tension is transmitted to the saddle support 26h; and in this case the rear horn of the saddle is so close to the free end ot' the main spring 2 that a portion of the said load will be eilt-active in producing an initial tiexure of the said end; the amount of such fleXure being` dependent upon the form of the liront horn, and its manner ot' attachment to the more rigid intermediate part of the primary suspension member. lli/*hen thesystem is subjected to an increased load stress or compressive shock, the upward thrust or the link bar 36b rocks the lever on the fulcruin pin 33" and thus imposes a progressively increased tension on the supplemental suspension coils 24M-24"; and as this movement continu-es, the inner end of the main spring,

is also indirectly subjected to an augmented bending' strain by reason of the greater pressure exerted on the saddle connection Q61. But these tivo spring elements still continue to act in series-li. e., the supplemental coil springs act as an elast-ic suspension for the adjacent 'part of the primary l-ea'f springuntil the vertically flexible linkage 7-1411, has reached its compression limit (position C). As soonas this occurs the load stress on the body bracket i8 Will be transmitted directly to. the adjacent end ot the main spring 2; and the primary and secondary suspension units Will then act in parallel, to reinforce each other, against further compression of the system.

The angular movement of the lever 301 on the fulcrum pin 33h, lifts the outer end of the lever and its associated fulcruin in 3J), and thus raises the plunger 5l in the cylinder 52. As the plunger rises, the valve `guides in the bracket arms t9-4:9

53 opens andv alloivs the oil above it to lill the bottom off the cylinder below the fjilfungeix When the coii'ip'ression of the system' is arrested, by tl'ie-} rogi'essive flexing of the suplilemental and main springl ele- 'ments, the rapid recoil oit thel compressed sion ot trapped air to etliect the desired result.

HlVhen' the suspension system is returned to the condition ofstatic equilibrium and is.

carriedbeyond the point of balance-either by the efiect of kinetic inertia or by an expansion stress-the increased'separation of the body and axle members imposes a pull `on the linlr connection tbgvand this ioclrs the lever 30" on its fulcruin pin 31h, ivliicli is noiv supported on the bottom oi the slot v (see Figs. vT` and 8l. This angular movement of the lev'er on the ulcrum support Sibis relatively much more rapid than its angular movement on the support 33",; and the resultant compression oft the vsup'plemental coils, 24h-424, greater for a given linear separation or ei:- pansion of thel body and axle members, than it is for` the* saine linear movement ot' approach. rebound movements of the system are very quickly and effectively checked by the supplem'ental-series-suspension4 action ot the secondary springs alone; but in the case oit an excessive or abnormal expansion of the parts'the guide linkage fl-lab, etc., Will be brought to rebound limit (position ll) and will then act a solid or longitudinally rigid shackle to positively vcouple the body to the inner end of the main spring', and thus bring' the latter into parallelreinforceiiient-relation vvith the secondary "suspension unit. And when the separation ot thebody and axle members has rocked the lever SOI through the angle, ahr, the bolt 331 Will engage with the bottom of the guide slots ofthe bracket 50, and Will thus positively and concurrently arrest any further 'expansion ot the system and any further lecure 'of yits elastic suspension elements.

Bui-ing the last ldescribed action theV opposite movements ot the plunger .5l-Which is held in hXed relation to the body supported fulcrum pin 31h-and of the axle is correspondingly. much In consequei'ice ot this the usual .leaf spring 2 is provided supported cylinder 52, Will again admita quantity of oil to the lower end of the cylinder; and on the reverse or return movement of the parts this oil will be trapped belowf the plunger, and will act, as before, to restrain and damp the recoil of the flexed springs to their normal load positions; and ivill thus eliminate the effects of a violent and uncontrolled reaction of these resilient elements from an abnormally strained position.

The damping control unit-comprising the parts 51-52-53, etcmay be omitted, ivithout changing the essential character of the series-parallel (or suspension-reinforcement) action which characterizes my improved organization; and any accidental loss or injury of the said control elements will not interfere with the proper operation of the other parts of the organization.

In the structure illustrated in Figs. 10 to 13 inclusive, the outer end of the main side with an eye bolt 17 c which carries tivo hardened steel rollers '5o-55; and the usual shackle coupling that connects this main spring end with the body member 6 is replaced by a two-part guide bracket that is secured rigidly to the said member by the bolts 116-7-56-.57 and 58. rl`he outer part of this bracket consists of a recessed cap, 59, which receives and guides the eye bolt rollers 55-55 (see Fig. 12); `and the other part consists of a longer U- shaped channel member, 60, which is provided at its inner end With a fulcrum roller 553C, and Which 1s widened at its other eX- tremity to fit over the edffes of the cap part 59; the two parts being clamped together both by the bolts 11c-56-57 and also by the bolt 61. The front edges of the vertical portion of the member 60 are turned inwardly and connected together at the bottom by the flange 52, to form laterally rigid guides for the edges of the main spring 2 (as best shown in Fig. 12). The assembled parts therefore constitute an effective double guide connection between the body and the outer extremity of the main spring, which Will prevent any relative sideivise play of these tivo parts, but which will permit of a certain range of free vertical movement thereof; theextent of said movement being` limited in one direction by the engagement of the rollers 55 with the bottom of the recess in the cap 59 (dotted line position R, of Fig. 1() and full line position of Fig. 11), and limited in the other direction by the means described later.

lhe supplemental spring element of the construction novv under consideration consists of a relatively flexible multiple leaf spring 24C, the base of which is rigidly secured to the stiff central portion of the main spring 2, by means of the clip, 26, and the end of which is slidably engaged with the outer extremity of the curved lever member 30C. This lever is mounted, at an intermediate point in its length, 'on the cross bolt 31c that may be conveniently carried by the clip 26, and is flexibly connected at its inner end to the vehicle body by means of the strap 36C and the adjustable block 37C. The outer end of the lever is pivotally coupled by the pin 63 to a U-shaped head 27C, which slides longitudinally in the grooves 64b-64, formed between the sides and flanged edges of the assembled bracket members 59-60 t as best shown in Fig. 12), and which is provided With projecting ears, 65, that are adapted to engage the rollers 55-55 of the main spring eye bolt 17. The head 27 is also preferably provided u'ith friction plates (it-66, which are loosely carried on the ends of the pin (33 and which are engaged, on their outer faces with the sides and edges of the grooves 6er-Gil, and, on their inner faces, by the ieveled edge portions of the head 27C (as best shown in Fig. 13).

The functional performance of the last described organization is also substantially the same as that which characterizes the constructions shown in Figs. 1 to 9 inclusive; and will require, therefore, only' a very brief explanation. lVhcn the organization is subjexted to compressive shock, the relative approach movement of the body supported fulcrum roller cfand of the axle supported main spring clip 26C, will rock the lever 30C in a clockwise directionfrom the position, l\l-il, shown in full lines toward the position C-C--c shown in dotted lines in Fig. lO'thus producing a progressively vincreased flexure in the initially tensioned supplemental-suspension spring 24. During the first part of this movementrepresented, for example, by the linear displacement N-C 10)-the outer end of the main spring 2 is free from load; but the relative doivnivard motion of the lever actuated head 27c soon brings the ears 65 into contact with the rollers 55; and after this occurs the compression stress is not only carried in parallel by the mutually complementary suspension elements, but the subsequent fontinued flexure of those elements is substantially equal in amount. Then the system is subjected to an expansion stress-d `which separates the body and axle parts beyond the normal. load position of Fig. 10- the lever 8Oe is again rocked in a clockwise` directicnon its pivot support 31 by th(` pull of the flexible strap 36C; and the supplemental 'spring is again increasingly flexed-A as shown in Fig; 11. The pivot supports and connections of the lever 30C, are so arranged that the angular defiection of the lever-spring elements is much greater' for a given linear separation of the body and axle parts than it :is for the same compression or approach movement thereof; and the elastic checking lll) the eye bolt rollers and Will force the main spring down-iu parallel with the sti-,p-

vplementalsprinni-miti,l the lc'onci-nfrent positivertlexure ot' both is arrested by the con-` tact ot the Yrollers With the bottom oli the recess in Which they move (see full line position, R, Fig. ll). During any doWnn/{ard movement ot theleverj head- 27", the friction plates (i6-(SG are relieved ot pressure; but in any return upward movementfrom either a compression or airefipansion displaeemeutthe Lsaid plates are forced out- Wardly. by the coaction olf-.the beveled p0rtious on the plates and the head, andV are pressed tightly against the faces ot the guide grooves- (f-l-(if. The frictional resistance thus interposed to the recoil of the flexed suspensioi'i meinl'iers dam-ps and restrains any violent reaction movement from aposition ot extreme displacement, and thereby aids iu preventing, or in very quickly extinguishing, any continued inertial oscillations ot the springr connected parts. Butv this damping,y means may be omitted, as in previous cases, Without changing the nature and tgeneric character ot' the structure on which it used.

lFigs. il and 15 diagrammatically depict another application of my in'rprovemeiits to a 'lront axle support., In the structure here shown the inner end oi the main side leaf springn is coupled `to the central portion of the body tran'ie by means of a vertically iiexihle, butlaterally rigid guide connection, which comprises, a V-shaped linkage .trame similar to thc ones shown in Figs. 1 3 and i'. and a broad elastic strap or bandf 67, that is clamped to the body block 486-. and is flexibly connected, at its other end, to theV lower element `llfl of the link-age guide trame. rlhe upper link 7d ot' this 'frame is lnovided with a hardened steelv roller 68,

that supports the Aend 'of the supplementalleaf sprinoj 2id; and the stili base portion oft this"spring,l is bolted rigidly to a lever trame Pill, which is pivotally supported, at an intermediate point in itslength, on the cross bolt 33" of the lJ-shaped body block 35d. The forward extren'iity of this `lever trame carries a roller 3l, which is adapted to engage with the upper side otl the :front axle block` 5; and the opposite extremity ofthe said trame is connected to the relatively stilll` central portion ot' the main spring 2, by means ot thel folding or collapsible .link coupling, 36, and the clip 37d. The lever member is also' preteralilyv provided with a one way friction check mechanismA which comprises tivo pair of co-operating disc elements. @6d-(39 andl GGL-($9, that', are mounted tol revolve freely on the shouldered ends ot the cross bolt, 33d,l and a plate 7,0` which is no'nrotatab'ly connected to the hub et the lever (see F l5). The continuous faces otl -l-'he friction` discs (56#69 are maintained in'constant pressure engagei-nei-it with the Vopposinaj yfaces ot? the connected lever a`n`-d VThe operation ot this mechanism is as fol'- lovvs: vlf'hen the body and axle partsI are torce-d toward eachother towardthe dotted line position Q-c) the lever frame, 301,- is rocked in a coun-tercloekvvise directiorn by the pressure enga-gement ot the roller-31d with the axle block, the collapsible .linl connection 36l bjeingr folded up .into the dotted line position, C, -c)land1 the initial load tension ot the supplen-iental-suspension springt is progressively augmented to resist and check the kinetic compression ot the .systen'n Conversely, when the parts expand beyond the'normalloadposi-tion` off Fig?.d lil. the mill ofthe' tension links 3G a-,Qgainv rocks the lever 30 in the san-1e direction as betore-but at a greatly acceleratedratio oft' annular-linear displacementof the engaged elements-and the positive lleigure ol? the secondary lea-tf sprung-v is rapidly increased to quickly arrest the rebound action ofthe organ-ization Both the compression and the) expansion n'ioven'i'ents are; at first,- resistefl almost entirely by the elastic lexui-'e o'l the suspension unit', 24tl;-the inner end ot the' main spring' 2 being free tol move through the range N*C-N- RN, without benin` su'lfijectedv to any strain, other than n that transmitted to it, in series,through" the roller (it and the linl'fa-n'e ZL-14d, supplemented by the rela-tively slight flexural strain-.in the elastic guide element Gi'.l But,- as these displacements increase in amplitude, the arms of the ,ejuidelinkage are locked Y aga-inst further free vertical movement, by the contact' ofthe arm 14e with the roller 68.- or bythe engagement ot' the stop 23 with the link T-Fl; and` aljter this occurs the main springv actsy in parallel with? the supplemental spring` 24d; and the tivo resilient suspension men'ibers n'iutually reinforce each other to' restrain andabsorbl tl'iee'lliects ot the more severe stresses and shocks of service. Any movement auf'a-y troni normal' load position` carries the roller pawl T2 out ojlppressure engageuientwith the flanged discs 66d,- 66d, and pern'iits the entire disc systemto rotate as a-'unit with the lever head; but when the reactive or return movement beginsf the member T2 is Wedlred into the triangular openings between the said flanges and the base' of the block 35d;4 and the discs 66v are sie held stationary with vrespect to the othery the structure depicted in Figs. 14 and 15.

ln this sixth illustrative exempliiication, the outer end ot the main side leaf spring 2 is ,operatively coupled to the body hanger (i by means ofthe vertically flexible, but laterally rigid, spring-link elements '7e-140, which are pivotally connected to'the cross bolts 11e and 17erespectively, and which are limited in their range of closing movement by the Contact engagement of rollers or washers on the ends ofthe hangerV bolt, 11e,`

with the upper faceof the link bar llre (see upper dottedline position Gof Fig. 16). The latter-ineinber is also provided with an inwardly projecting flange or cross head to which the end of the supple-mental leaf` spring 24e is rigidly rivetedgand the base of this spring is boltedfto a lever vmemberA 30E, that is shackled to the-body bracket by the swinging links 'l5-75 and the crossbolts' 33e and 7 6. The inner end of this lever "member carries a `roller 31e, that isl adapted to make contact engagementfwith theflattened top of the axle bracket 5; and the forward portion of the said member is coupled to the stiff central part of the main spring, 2, by the flexible strap, 36e,- and the cliplTQ. The lever 30e is provided with a curved rib or tonguev 3Se that is adapt-ed to inake contact with the body frame and thus limit its counterclockwise rotation on the shackle bolt 33e. This cuived rib may also be utilized as one element-of a. friction check mechanism which comprises a dovetailed'slot in the base of the body bracket, 35e, 'and a wedgesliaped; block 39e that is fitted'closely therein, and is kept in pressure engagement with the said rib by the concealed spring 40e. When this Vassemblage of parts is sub- 5)ected to compressive stresses, the relatively Aopposed,movements of the axle and body blocks 5 and 35e rock the lever 30e in a clockwise rdirectionl onfitsshackle link supports 5. and this increases the initial suspension tension of the supplemental leaf spring 249. In

this case the iexural strain inthe supplemental spring is transmitted directly to the' outer ond of the main spring through the link connection lele; and the two elastic suspension elements act in series, until the continued approach of the main spring and body'parts brings the link frame lele into rocking engagement with the end elements of the bodj,1 bolt 110,' and thereby puts the primary and secondary springs mtoparallel or reinforcement relation to each other.

Vhen this organization is subjected to a rebound or expansion stress the separation of the body and main spring members imposes a tension on the flexible strap 36, which is connected to the lever 3()e vat a point relatively close to the pivot bolt support 33"; and this produces a correspondingly accelerated flexural movement of the lever-actuated-supplemental spring, kthat is again transmitted in series to the outer eyeendl ot' the main spring, and produces a concurrent positive bending thereof. During these angular movements, of the lever 30", in a clockwise direction, the curved rib 38e lmoves downward, away from the bracket 35", and the block 39e is forced backward by the lspring 4.09, toward the position. shown in Fig.. 17. lVhen the parts react, or return toward the normal load position, the counterclockwise rotation of the lever is retarded by the frictional resistance of the block 39 to forward movement; and the quick or free recoil of the flexed springs is thereby effectively restrained and damped.

In the 'organization shown in Figs. 19 to 22 inclusive the linkage which connects the outer end of the main spring` 2 with the body scroll iron 6, comprises the H-shaped outer link, Tf, and the forked, or U-shaped, inner link laf, flexibly connected by the pintle or hinge bolt QO; and the linkage permits of the relative up and down moveinentof the connected members from the full line position of Fig. 19 to the dotted line position C Vof the same ligure, or to the full `line position of Fig. 20, without allowing the relatively moving parts to swing or sway outof proper vertical alignment. The link frame Tf is also provided with a supplemental cross pin (3S that passes through the eye of the secondary leaf spring` Qdi; and the base of this spring is bolted to the outer end of a lever member 30f that is connected,` at'its inner end, to the axle block 5, by the link bar 36t and the clip 37f. The. lever 3()f is suspended between the two side arms 23T-32% of ya second lever frame, by means of the swinging links f-75f; and this second lever frame is, in turn, rigic ly mounted on the cross bolt 33f that is rotatably supported in the forked body bracket 35f.` The outer extremities of the arms "w" are reinforced by the inwardly turned ribs `theA link SGf- Leveren platesot a one way rotary tri'ction check mechanism-5 andthe other elements `ot this mechanism comprise the tibre discs 6924592 the flanged metal disc TOf, the drinn 80, which is rotatably mounted on the central portion ot the Vcross bolt 33, and the-springs Tlf, Tlf, etc., which serve to maintain the various :Friction disc surfaces in constant pressure engagement. The flanged peripheries or' the disc member, 70'?, and ofthe drum, 80, are notched to torni ratchet teeth; and the drum 8() carries a rotatable collar Sl which is provided with. a cross pin 82 and a pair oli pawls 83*88, that engage with the said teeth. A second 'set ot pawls 84E-Sli, are mounted on the cross pin 83 ot the bracket 352 in such position as to also engage these ratchet teeth and prevent any connterclockwise rotation ot the members TOf and 80. The collar 81 is grooved` to receive a flexible band 86, that Ais secured,` at one end to the rotatable member, and at the other to the axle block clip-37"; and a pair ot spiral springs Sil-ST are attached, at

their outer extremities to the ends ot the pin 82, and at their opposite extremities to the side forks ot' the bracket 3;'3.

F rom a structural point ot View, the organization last described differs from those previously considered in having two lever actuated supplemental spring units,24 and 79, that are separately attached to the lever elements Sor and 32. This change does not, however, affect the general operative character oi' the coiiibination. Wheii the parts are in the position. ot static equilibrium, the' 'outer end ot' the `lever frame 3? isin engagement with the body traine (it'ull line position oit Fig. 19) g and the supplementalsuspeiision-springs Af andTQ-TQ then under su'tlicient initial tension to relieve the outer end ot the main spring 2 trom all` stationary; but the other leverBOf, and thev lea-t spring :24? attached thereto, are rocked in a clockwise direction on the shackle link suspension T5"7if, bythe upward thrust ot This produces an increased tension in the secondary spring Qdi, which is transmitted, through the pin support` GS, and the vertical .link Tf, tothe body hanger (3. The approach o'lI the body and' main spring members and of the spring heads 2li-2.7i and 2G also produces a corresponding linear compression ot the` coils 7 9-7 9, that cooperates with the magnied flexural action oli' the levers-spring elements, :itil-241, in resisting and restraining the clef' g movements ot' the said members In il first stage ot the compressive action, the cuter end ot the main spring, 2, is tree so more vertically with respect to the body;v but when the guide link lllf' has rocked upwardly to the dotted line position C" l 19), this free movement is arrested by the lengagement ot the said link with the suppleinental-spring-connection, f GSff on the other linkage guide element Tf. The .locked linkage arms 7f-llf then actVas ay rigid shackle, to couple the adjacent main spring` and body parts to each other g, and alter this occurs the `primary suspension eleinent is brought into parallel flexural operation with the secondary7 suspension elements; and all of these elements act, as mutually complementary reiniforcenient units, to rapidly check any unusual or excessive. coi'npression ot the system. Y

During the closing movement ot the body and axle parts the depending portion ot the strap, 86, fis shortened, and the collar 81 is rotated to the leftby the expansion olf the spiral springs SlT- without moving the triction disc elements. But when the reverse movement begins the pawls engage with the toothed peripheries ot' the disclmembers, TOf4 and 80, and the right handed rotation of the collar ll-which is necessitated by the separation ot the body and axle ineiny bers-is now resisted'by the trictional engagement of the mutually rotating parts 'mf-80, Withthe relatively fixed heads ot the lever frame 321, and the interposed libre discs 69% This rictional resistance clamps thel elastic' recoil of the flexed springs, and thus prevents any violent overthrow or inertial rebound ot the parts past the initial loci f of static. equilibrium` But whenl the body andl axle members are separated beyond this normal loazd position, by any unusual rebound or expansion stress, the downward pull of the link 36f rocks both levers, 0f32f, as a unit, on the trunnion supports ot the cross bolt 33r-- (the independent conneV terclockwise motion of the lever() being now prevented by the stop action' of the cross bolt 78)and thus concurrently subjects the spring fend 79 79 to a magnitied and progressively increased tlexure, that will energetically restrain and promptly checksuch opening movements. This series-suspension tact engagementwith tliecross bar-'ot` its companion element ff.; and the twoI locked elements then serve to shackle'V theV primary ,suspension `inenibei" to the end ot the body hanger 6, and to thereby bring the. said member into parallel or reinforcement relation to the secondary` suspension` springs 24U and H f" Durino the clockwise rotation of the lever gtramefBQf, all of the parts ot the frictions check mechanism, 69f to` 86 inclusive, move concurrently therewith; and do not therefore interpose any resistance to the elastic restraint ot the expansion movement. But when the movement is arrested the flexed resilient elements ot the suspension system 'tend to quickly recoilthis tendency being these springs are pivoted respectively to thev lower and upper barsltg and Tg, of the vertically tlexible, but laterally iiigid, guide linkage which serves to operatively connect the extremity ot 'the main spring 2 with the body hanger G; and the inner base portions ot the said springs are bolted to the associated lever members 30g and 32g. :Thelower lever member 30g is suspended from the central and relativelyT rigid part oit-the main spring, by means of'. the Vswingingr shackle links SS and the clip bracketg; and is provided at. its inner end withva Vtnlcrum roller that adapted to engage with the body bracket 35g. rl`he upper lever is suspended from this same bracketby the shackle links 75S; andis pivotally connected,

at an intermediatepoint in its length, to the upper end of the links 36g. The lower ends ot this last mentioned pair otl links are rigidly conjoined by a cross bolt 63g, which vcarries a slotted block 39g that. is adapted to closely engage the lower curved edge of the first lever 30g. A pair of tension springs 40g are connected, at one end to the body bracket 35g, and at the other end to the intermediate parts of the links 36g,l and serve to pull the latter to the lett when the body and axle members are pressed toward each other. This phase of the movement rocks the lower lever, 30g, on its fuk-.rum roller support 31g, and thus permits the block 39g to slide inwardly, along the curved edge on which it bears, without affecting the position o'tl the upper lever 32g: The counter-clockwise rotation of the lower lever also progressively increases the initial suspension strain on the compression resisting supplemental spring 24g, and a small part of this strain is ti ansmitted, through the guide link member 14g, to the outer tree end of the lmai-n spring. rllhe two springs 24g and 2, are thus con nected in series and continue to act in that relation. until the closing movement o't the system brings The supplemental spring eye connection withthe link bar 14g' against the f main spring 2 (see dotted line position C); After this occurs the load stress on the rear end ot the body may be transmitted directly, from the hanger bolt 11e and upper link Tg, to the adjacent part ot the primary suspension-member; and the primary and secondary springs :2 and act in parallel to mutually reinforce each other against ilurther compressive tlexure. Then the return movement begins, the normally rapid recoily o'tl the strongly vflexed leaf springs is restrained by the combined frictional and spring resistance to the right hand move ment of the links 36g and the block 39g, and the consequent rictional drag on the downwardly moving lever arm 30g. lVhen the parts have been restored to normal load positionk the central portion ot the spring` 24g is in contact with the adjacent portion ot the main spring` and is thus n'iaintained under the initial tension required to carry the static load. Then the body and axle members are Jrurther separated-by a rebound or expansion stress-the lower supplemental suspension springis still held in substantially fixed relationship withv the main spring,v and the concurrent movement ot these suspension members, away from the other secondary spring 79g, imposes a continuing pull on the links. 362-365', These links are now held in approximate alignment with the suspension links 88-88g and` as a consequence of this. the longitudinal stress on the connections, 36h-88, is princivpally effective in producing a largely magnified angular movement ot' the upper supplemental lever-spring members 2g-79g.,u

anda correspondingly increased flexural resistancein the upper spring-to the expansion of the system. The strain in the spring TL- g is transmitted to the upper guide link 7H through the cross bolt connection 68g; and this serves to accelerate the tree opening movement ot the linkage trame until the cross bar of the upper link comes into eni agement with the extensions 23g ot the lower link 14g. After this occurs the primary and secondary springs 2 and 79g act in parallel to restrain 'further separation of the body and axle parts. In this ease the quick recoil kot the ysupplemental rebound check spring 79S, is Jrictionally damped by longitudinally corrugating the individual leavesso as toincrease their area ot sliding contact and providing an elasticl compression clip at the terminus ot each leaf-as shown in Fig. 22B- to increase the trictional pressure engagement ot the sliding surfaces.

Figs. 24 and 25 illustrate another embodiment of my invention in which two separately actuated counteracting spring units are employed to respectively resist compression and expansion movements. The lirst ot these units comprises a pair of helical coil springs, 24th-04, arranged one on each side other endv` to the. inner extremities ot a double arm leve-r 30-30h, which is pivot ally lsupiiorted, at 33h, on the body bracket bh. rlhe second unit coiisists ot.' a multiple lea'tl spring- 79 that is pi votally cmipled, at its eye end, to the l'l-sliaped `link barT lfl-l, and is bolted, at its base` to -a lever 32h; which is also suspended from the 'bracket 235 by the swinging' links T The second lever is suspended between the 1arms ot the first flever; and the intermediate ]')a1;'ts o'li both o'l: these. springh aetuating members are operatively connected to the axle brackeh by .means oit' the long cross bolt 90, the links 36h-36h and the axle clip 37h. The base o'tthe leat spring` 79 is provided with beveled notches which receive the Wedge shaped blocks G61L--5Gh that are adapted to frictionally engage the adjacent faces ol. the leverl arms 30-30: and in order to more ettectu'allv resist the outward thrust of these blocks the said arms are rigidly bound together, at their opposed edges, by the spacci.' block and bolt members Sil-92. In' this `construction the vertically liexible. but laterally rigid guide linkage connection` between the inner end oi the front side leal1 spring' 2 and the body bracket 48", is ot quadrangular torni; and comprises the tivo main links 7h and 14 (the lutter ot which supports the eye end ot the secondary lea-t spring 791 and the two auxiliary links 7 and lllhh.' The tree vertical rai ot i'novement of this link 'traine limitedin one Vdirection by the engagement between the upper member "Zh and the vcross' bruo't lower member 14h, and in the 'other directionby the engagement ot this saine cross barh with the'xaiifiliary member 14m.

The functional action ot the various elements ot th-e last described organization "will be readily understood, Without extended explanation. Then the parts are in the normal load position, the spacer lock 91 res-ts on the shackle supported end ot the lever 32h: and the central portion ot" the asso'- ciated leaf spring;v 79 is in pressure engagement With a block, otresilient or seiniresi lient material. which is mounted on the body frame., The counteracting' secondary springs 24h and 79h are thus maintained under such respective initial tensions as arenecesthe leaf spring 7911; and the `liemural strains in both springs-are at tirst transmitted in se# ries to -tlie adjacent portion oit the main spring .But as this approach movement continues the link arms 71 and' ll-hengage each, other, and this converts the vertically flexible guide linkage into 'a vertically iniex-` ible shackleconnection that directly trans` nitsa portion of the loadlstress to Vthe eye end ofthe primary suspension member.y `When this occurs further direct iiexure of the secondary `leaif spring` 75) 'isariestedg but'the continued closing nioveniei'it ot the parts is energetically resiste'dand quickly checked by theronioined action ofthe main spring 2 and the supplemental coilsprings Qatlllll which new act in parallel`v torefinforce each other against excessive compression. l

illhen'the parts havereturned to normal Fig. 24H-land are subjected toafreboundor expansionstress; the cross bolt'QO engages with 'the upper' not hed'edgeot the lever 3211, rocks the said men'iber downwardly lon its shackle suspension 75, and thereby7 imposes a greatly augmented braiding strain on the upper supplementalleaf spring 79", This movement does not aliiect the position ot the lever 30 which ren'iains at rest on the shackle supported end ot the lower lever gbut the linear separation ot the lbody `and oit the axle sujgipoii'ted main vspring' imposes an equal linear extension on the lcoil springs `blllfl'l. the increased tlerural strains on both the upper andv the'lmver supplemental springs are transmitted to the main, s'nfing thi'ouejhV the link connection 'lflfh and theclip connection 26h: and' these springs therefore actyas series suspension elements, Until such time they are brought intoparallel operative relation to the spring by the locking' oit the opening linkage trame (as betoreexplained and the consequent shacklinp; of the prin'ia'ry suspension memberfto the liiodylnacket 48h. Any ence tore res edf-like any excessive compresF sion move1nent--by a parallel, or reinforcen'ientg action' ot the main and supplemental spring elements; and an abnormal overthrow or rebound ot the resiliently 'supported parts is thus effectively and quickly arrested. 4

-The positiver` or .toi-Ward, angular Vmoven'r'entsol? the levers 30 and 32h-. e., the upwardsiving ot the lever 30h or the downivard'siving ot the lever SQh-arenct' accompanied by `any' 'trictionilf damping* action;

but when the return moven'ient begins the' Wedge shaped blocks 66h vare Vforced out-vr wardly (by their l engagement' With'fthe y spring and the recoil of the" flexed springs`,'

beveled notches `in the sides of the 79h) .1 .troni either position of displace'ment` is r'etarded and eased doWnWbythe lfrictional" engagement between 4those blocks and" the" expansion n'iovenient is there'` ies contiguous faces of the arms 3211. This relatively simple-arrangement or' parts is theret'ore effective in damping the reactive move-- ments of the system eitherfrom the position ot compression (dotted line positionC-c, etc.) or from the position ot rebound (dotted line position R-r g but the general operative character ot the organization will not bc changed, nor willv its action be prevented or disturbed, by the removal or accidental loss olf th'e friction check elements.

Figs. 2G to .29 inclusive show a very simple `form ot counteractiiig-supplemental-spring construction which is adapted to utilize my invention in conjunction with the side leaf spring` suspension oi a truck axle. In this lexemplilication ot' my improvements the usual rigid shackle support for the outer end of the main spring 2, is replaced by a longitudinallyY grooved guide frame, that comprises the two side bars that are rigidly secured together bythe shouldered cross bolt 1.11 and the spacer block and bolt connect-ion 611; The grooved sides ot' the bars, 9,5, are adapted to closely engage and guide the edges ot' the main spring eye and the shouldered pin 171 which .is se cured therein; and the range of tree vertical movement ot' these main spring parts is limited and determined by the lengths ot the guide grooves. The supplemental-complemental suspension reinforcement unit, which cooperates with this vertically flexible, but transversely or laterally rigid guide connection, comprises the following elements, to-wit A single volute coil compression spring 241 interposed between ka main spring support Q61 and the head Q71; a pair ot helical coil expansion springs 791-791, positioned one on each side ot the main spring andconnected thereto b v the clip bracket' 371; and a lever member 301 that rotatably mounted on the cross bolt 381 of the body bracket 351, and is suitably connected, at its opposite end, to the spring head 271, and to the cross bar support G81. otl the coil springs 791 791. The central part of the crossbar G81. is coupled to a vertical link rod B61, which slides longitudinally in the tubular guide extension, 9G. ot the bracket -l71-,and which is normally in pressure enga gement. Vat its lower end, with the upper tace of the main spring 2. The head 271 is also provided with la tubular extension 97 whichis slidably engaged by the head ot a bolt 98 that is screwed :into the main spring clip block 261. The outer and shorter arm ofthe lever 30* is normally in engagement with the lower side ot the body block 351 (as shownvin Fig. 26) and it is preferablyrprovided with a rocking friction. drum 391,v which is mounted on the cross bolt 99,

and which is held in frictional engagementl with thecurved recessed face ot the .body block 351 by the concealedspring 401.

In the normal static load position ot the parts all ot the coil springs, 24:1, 7 91-791, are maintained under a predetermined initial lexure-the 4iirst bythe tension engagement between the tubular member 97 and thc-bolt 98 which limits the` separation of the heads 261 and 271, and the secondiby the pressure engagement between the rod i361 and the main spring 2 which correspondingly limits the approach ot the tension spring supports 371 and G81-and the initial compression of the spring 241 is sul'iicient to elasticallysupport all that part ot the static load that would ordinarily be carried by theouler end of the main spring 2. lVhen the load stress is augmented by akinetically imposed shock the main spring and axle parts are vforced upwardly; the head 261, the link rod 361 and the inner yend of the lever 301, are all concurrently lifted-in unison with the main spring-#while the outer extremity of the lever, together with the head 271 are correspondingly depressed, and the volute coil member 241 is thereby subjected to a magnilied linear compression that acts. in series with the main spring, to ellectively restrain and cushion the elect ot minor shocks and jars. It the applied stress is sul'liciently great to force the main spring eye bolt 171 into engagement with the upper ends ot' the grooved side bars 9:3-#95-and thus permit of a direct transmission of the load from the body hanger G to the primary suspension member-'the two resi-lient support elements 2 and 241 willthen act in parallel, and their mutually reinforced elasticresistance Vto ttul'- ther tlexure will quickly check and absorb excessive vibration and abnormal compres sion shocks. When there is a reverse 4expansion movement of the system, the separation ot the body and main spring brackets and 261, and the tensioned connection, 97-98, between the bracketV 261 and the lever supported head 271, cooperate to rock the lever in a clockwise` direction. on its pivot bolt 331, vand thus lilt the inner end thereot away from the main spring. The opposed displacements kof the tension springl supports, G81 and 871,r impose `a greatly magnified ller:- ure Von thev coils 791-791 (as indicated by the dotted lines R-R-v-r, etc. of Fig. 2G) 5 and this is sufficient to arrest any ordinary krebound movement without assistance from the main spring. But whenthe expansion of the system is unusually great, the main' spring eye bolt 171 will be carried to its` `net-aise ing, and the `drum 239i is pushed forward into the widened opening between these parte by the expansion ofi the spring` lOi (asbest sliowi-i` iii ilig. 27) l'Vhen the return n'iovenient begins the iioi'iiialll/,f (prick recoil ot the resi-lient suspension elements is retarded and daiiipcd b the lr'i'ictional resistance between the pres t engaged si'irt'aces ot the relatively i-iioving iiiiei'nbers 35i-?i9-.-9)- IlO. This one way trictioiicheck action is iiot however essential to the proper pei"- t'ofrifiiance of the suppleii'ieiiital-coiiiiplemental (series parallel) spring combination: that constitutes the main part oi" my vimpri-uved orzejanizatioiigV and that action inay, in previous cases, be either utilized or dispensed with, as circun'istances may require.

The construction to be next considered (that shown in the single view of Fig. 30) resembles in many detail respects, thecoiistruction last described. lt comprises a body bracket 48 which has two downwardl'v proj eating;v side bars,` GO, that closely einbrace the outer faces of the Ui-shaped link lllk; "andv a broad ViFlleXible band 7 which connects the cross bar ot: this llink with the base o'lf the bracket 4S;--the whole constituting` a vertically flexible, but laterally rigid, guide connection. between the body member 81" andthe adjacent inain si'iring eye on which the link le is pivotally mounted. The range of free vertical movement that i's allowed by this connection limited by the cross bars at the ends of the guide plates kg and this range is, as in previous cases, preadjiisted to obtain the desired ratio between the series-susijiensionaction and the parahel-reinforcement action ot the supplemental spring unit of the combination. This unit consists of a single volute coil spring Q-lk, which is supported on tbemaiii-springaxle bracket 26, a multiple 'leat springl which is connectedat its inner end to the linkll-k by the ,swinging shackle 68k; and a lever member 80k. which is fulcruined on the cross bolt 33k ot the body bracket 35k, which is bolted, at its opposite extremity, to the base of the spring` 79k, and which is also pivotally connected, at an .intermediate point, with the upper head or cap, 27k, of the spring,- 24k. The cap 27k is provided with a tubular extension, 97k, which is adapted to receive the coned head ot a bolt.98k,that is riveted into the lower bracket support 26k; and a tapered split collar, 39k is preferably interposed between the coiied head of the bolt 98k and the wall of the tubular eXtensioii 97k. This mechanism falso includes a slotted block 41k, kwhich engages the top and side. edges of the supplemental leaf springl 79k, and which is shackled to the main spring-aXle-bracket 26 by the telescoping link elements 995-100.

The operation `of this eleventh illustrative embodiment ofiny invention is as folthat part ol the .no'rizii-al. load that .is ordi- Y narily transmitted to the inner end oil the 'liront side leali main spriiig. lllheii the 'ein is compressed the lever 30 mained iii its normal load position by contact eiigaggeiiieiitofl" its inner end with the uiiiil'ei' side out.' the body traine; the`r suppleiiiieiital coil spring' 24k: is subjected to a linear Y compression which is equal to the linear ap preach of the body and axle parts g and the supplemental leaf spring 79 vis valso subjected to an increased tlenure by the relative ifipward movement of the main spring' guilt e link lill" and the shackle connection 68k. Both supplemental springs 2li and 79k therefore act in series-sifispension relation to the niiiainspring 2, until .the central bosses ot the link, 114k, engage with the upper cross bai oit the guide frame 60, a't'ter which the three springs act iii parallel-reintercoment relation. During' the approach movement ot the parts the bolts @SIL-l0() slide freely upward iii their associated connection elements iwf-99k; and the split collar 39".- wh-izcli is looselywpinned to the bolt 98k and moves upward therewithis relieved o'lV eX- pansion pressure. 'But when the closing,l inem-)nient is arrested, the reaction of the ticked springs moves the parts 97k, and 39h-"98k in `opposite directions and expands the split coll-ar against Vthe contiguous surot the tubular `exteiisioliii 97k; andthe frictional engagement of these relatively moving;y parts retards and clamps the recoil action.v Villien the system isexpanded from noi iiial load position, the expanded and tensioned connection 97k-98k, imposes la clockwise rotation on the Ylever 30k` andl thereby subjects the leaf springl 79k to a greatly iifiagnified flexural strain, which is transmitted, in series, to the shackle and'link connection GSk--lf-lk, andthence' to the free 'end ot vthe main spring. This 'series-suspension action continues until the relative! vdownward inovementoie the linkage 14k-7k brings the.V

hubs ofthe link'llk intoengagement with the lower cross bar of the guide frame GOk (see dotted line positions Rg-Rw-iL-r) and thus changes the series-suspension relatioii` ship otthe'partsinto a parallel-reinforcenient 'conjunction The iiiagniiiedv angular movement oll the lever-spring elements 30k-"Z9k allows the slotted block and shackle connection, Llill-9912400, to be drawn iiiwardly by thetension spring 40k as shown in dotted lines in Fig. 30) and when the return movement, toward normal load position, is initiated, the rapid recoil of the resilient support inembersis restrained and controlled by the frictional grip of the sliding block lll on the face and edges of the leaf spring 79k. f A Y' In the exen'iplilication of my improvements which is shown in Fig. 3l two coun-` teracting leaf springs, 24m and 7 9 are used as the supplemental-suspension-complemental-reinforcement elementsk of the system. The first of these elements is rigidly secured, at its base, to the body bracket 26m and is pivotally connected at its outer end to the upper ends of the links 36m by the cross bolt 31m. The other secondary leaf spring is pivotally coupled to the inner eye of the main spring 2, by the eye bolt 17m, and is bolted, at its base, to the lever element 30m, that is shackled to the central portion of the main spring by Athe swinging links 75m and the clip bracket support 35m. The outer extremity of this lever is pivotally coupled to lthe lower ends of the links 36m, and it is also preferably provided with a U-shaped thumb-latch 39m that is pressed outwardly, into engagement with the edges of the said links,vby the flat spring 40m. The cross bolt connection 31m slides in the depending slotted arms 49m of the body bracket 26In and is limited in its movement by the ends of the slots through which it passes. In the normal load position ofthe parts the outer end of the lever 30m is in engagement with theupper face of they main spring, and the cross bolt 81' is at the lowest limit of its arcuate movement'in the said slots; and the supplemental suspension element 24m is then under sufficient initial tension to maintainfthe system in static equilibrium. When the normal loa'd is augmented by a kinetic compression stress, the leverspring elements 30m-79m, and the links 36m are moved bodilyas a unit-'toward the dotted line position CC;` a`nd the initialsuspension-strain in the supplemental spring 24m is correspondingly increased'to balance the added load. As the axle and main spring members continue to approach the body members, the widened head of the main spring guide link 14' engages with the adjacent face of its solid companion link 7m; and the vertically flexible guide connection, 7m--1/lm--20m,v is then converted into a longitudinally rigid compression-shackle that will-transmit a load stress from the .body bolt 11m directly to themain spring eye bolt 17m. The primary and secondary springs are thus put in parallel, and are conjointly and equally flexed by any further closing movement of the spring supported parts. When the system is subjected to a rebound or expansion stress, the compression resisting spring 24m and the link connections 36m, are held in normal load position by the engagement of the cross bolt 31m with the extremities of the slotted arms 49m; and the relative downwarclmovement of the increased strainv in this spring is directly transmitted, in series, to the eye bolt connection 17m and serves to impart an increased 'liexure to the inner portion of the main spring 2, and thus accelerate, or rather accentuate, its movement away from the body. This kmovenmnt is ultimately arrested by the engagement of the lower edge of the link (head) ltm, with the stop extension 23m of the link 7m; and this engagement converts lthe guide linkage frame into a rigid tension shackle that is adapted to hold the spring eye bolt support 17m at a fixed distance from the-body bolt support 11m. The yfurther expansion of the system is then restrained by the parallel operation of the primary and secondary springs, 2 and 7 9m, both of which now react directly on the body member through this fixed shackle connection.

The thumb latch elements 39m-40m are provided for the purpose of securing some frictional damping action on the recoil of the resilient support elements from either position'of compression .or expansion displacementf, When the parts are moved from the full line position, N, to the upper' dotted line position, C, the linkarms 36mare rocked backward with respect to the lever 30m; and lwhen the rebound ory expansion movementfrom N to R-occurs, the `said lever is rocked forward, relatively to the said arms, to an even greater degree. This relative angular movement, ofthe last mentioned members, permits the .spring 40m to push the thumb latch 39m into a more nearly radial or perpendicular relationship to the arms 36m; and the frictional grip of` the latch ends on the edges of the links presents a substantial check to the sudden recoil `of the parts to normal load, position. This friction check device, may, however, be omitted without affecting the characteristic performance of the remaining elements of the combination, in cushioning and absorbing the lighter shocks and jars by a sensitive series-suspension-action, and'in restraining and compensating the effects of excessive stresses and strains bya more energetic parallel-reinforcement-action of the elastic elements.

The final exemplification of my improvements-which is depicted in Figs. 82 to 34: inclusive-is somewhat different in appearance from any of the previously described forms of construction; but it embodies the same general features of structure and operation as are found in all examples of my present invention. In the organization 

